Current trends in the connected wearable world lean towards multiple connectivity functions to enrich user experiences within a very limited design volume provided by most wearable electronic devices. In order to provide differentiation in an increasingly crowded market segment, industrial designers have gravitated towards the use of exotic and/or precious materials (e.g., titanium, high-grade stainless alloys, gold, silver, platinum, and similar) for the body or housing of the electronic device to provide an aesthetically pleasing and attractive exterior finish. Typically, the wearable electronic device wirelessly connects to other local devices such as smartphones, tablet computers, or other wearable devices using communications protocols such as BLUETOOTH® (BT), BLUETOOTH Low Energy (BLE), and Near Field Communications (NFC). In addition, the wearable electronic device may also connect to wide area networks (e.g., the Internet via IEE 802.11) and may, in addition, receive stand-alone satellite content (e.g., global positioning data via GPS/GLONASS/Galileo). The demands placed on the antenna systems used in such small form factor wearable electronic devices are extreme, demanding exceptional antenna performance to provide a favorable user experience when disposed proximate the user's body or closely worn apparel.
Modern electronic designs increasingly rely upon the use of touchscreens to provide a compact input/output (I/O) interface that provides the device user with an intuitive interaction with the device. Unfortunately, the digital touch module (DTM) used to provide touchscreen capabilities, typically introduce significant losses in antenna efficiency. The indium tin oxide (ITO) layers used in fabricating the DTM is a relatively lossy conductor (e.g., 150Ω/□) and high E-fields produced by the antennas disposed proximate a portion of the device the device couple to the DTM causing losses that often exceed 10 dB. It is believed the coupling of E-fields is due mainly to the fact that the top portion of the device body or housing radiates and produces a relatively high current proximate the glass surface of the DTM. The top portion of the device is preferred to minimize the user introduced losses, i.e. hand loss for a wearable device.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications and variations thereof will be apparent to those skilled in the art.